Abstract: A splicing means for welding light waveguides in or immediately at optical components is disclosed which includes an optical means for observing the ends of the light waveguides to be welded together and two oppositely directed electrodes arranged parallel but spaced apart from one another which affect the welding of the light waveguides by igniting an arc. Observation of the ends of the light waveguides to be welded is provided in the welding position by a stepped arrangement of electrodes whereby the electrode axes are offset from one another. Due to the stepped arrangement of the electrodes, the light waveguides can be observed in, for example, the region of a trans-axial channel of a light waveguide plug and can then be welded to one another in the same position.

Abstract: In welding optical fiber ribbons [by means of] using an electric arc formed between electrodes the region heated by the electric arc is mapped on CCD-elements in a camera. In the obtained picture the light intensity of those portions of the picture is determined which correspond to the heated fiber portions. This light intensity is used for setting the electric current flowing between the electrodes, so that a desired welding temperature is obtained and so that also a desired, lower temperature is obtained in the fiber ends in a preparatory softening stage, which has a long durability and which is performed before the very welding stage. This determination of temperatures [by means of] using measured light intensities gives reliable values also in the case where ambient conditions like the air pressure are changed, the state of the electrodes is changed owing to contamination, etc.

Abstract: When splicing optical fibers of different kinds to each other by means of arc welding, a matching of the mode field diameters of the fibers is desired. This is accomplished by prolonging (period 55) the heating after making the splice (period 53). During the prolonged heating the hot-fiber indices of the two fiber ends are continuously determined. Either one of these indices or some suitable quantity derived therefrom is all the time compared to a threshold value and when it is reached the heating is stopped. The threshold value has been determined in a preceding stage using test fiber pieces of the same kind in a splicing operation with prolonged heating. Then, in such a threshold level determining stage in addition to the hot-fiber indices, the transmission of light is constantly measured during the heating and when it has its maximum value the corresponding hot-fiber indices are stored and used for deriving the threshold value. This method of matching mode field diameters is simple and takes a short time.

Abstract: A method is provided for fusion-splicing with a laser beam two optical components, one of the optical components (e.g., an optical element such as a lens) having a surface that has a comparatively larger cross-sectional area than a surface of the other optical component (e.g., an optical fiber).

Abstract: The present invention relates to a method and apparatus for observing, before and after fusion-splicing of optical fibers such as ribbon fibers each including a plurality of optical fibers in particular, the butting state of the tip portion of each of fiber ribbons in a wide range with a high accuracy. In the observation method in accordance with the present invention, while the optical fibers to be fusion-spliced together are disposed on a predetermined reference surface such that their end faces butt each other, at least a pair of cameras are independently or synchronously moved along a direction perpendicular to the longitudinal direction of the optical fibers so as to change the shooting areas of the respective cameras, thereby realizing the collective observation or local observation of the observation area. The observation apparatus in accordance with the present invention comprises a driving system for moving the pair of cameras along a predetermined direction.

Abstract: A system and method for providing an optical coupler is disclosed. In one aspect, the method and system include a plurality of optical fibers, a first covering, and a second covering. The plurality of optical fibers further include a first end, a second end, a fused portion between the first end and the second end, a first interface between the first end and the fused portion, and a second interface between the second end and fused portion. The first and second coverings enclose substantially all of the first and second interfaces, respectively. In a second aspect, the method and system include a plurality of optical fibers and a covering. The plurality of optical fibers further include a first end, a second end, a fused portion between the first end and the second end, a first interface between the first end and the fused portion, and a second interface between the fused portion and the second end. The covering encloses substantially all of the fused portion, the first interface, and the second interface.

Abstract: A light branching and coupling device excellent both in transmitting performance and in distributing performance in which the intermediate portion of an optical fiber 10a (10b) is thermally drawn to form light transmission fiber portions 11a and 15a (11b and 15b) and a light branching and coupling fiber portion 13a (13b) having a diameter smaller than that of the light transmission fiber portions and, at the same time, form tapering fiber portions 12a and 14a (12b and 14b) between the light transmission fiber portions and the light branching and coupling fiber portion so that the tapering fiber portions are tapered off gradually toward the light branching and coupling fiber portion 13a (13b) side. The light branching and coupling fiber portions 13a and 13b thus formed are fused with each other.

Abstract: A splicing device for welding optical fibers in or close to optical components, in particular optical fiber plug connectors, comprises a first receptacle for the optical component and the associated first optical fiber, an axial adjustable second receptacle for the second optical fiber, an optical device for observing the optical fiber ends to be welded, and two electrodes arranged at a distance from each other, with the first receptacle being mounted so that it can pivot about a pivot axis that is aligned parallel to an axial direction in such a way that the end of the first optical fiber that is located in or close to the optical component can be pivoted in between the two electrodes.

Abstract: A pre-fitted optical fiber section (2) is held in a plug ferrule (1) in such a way that it extends from a face (3) up to a lateral fusion access aperture in the plug ferrule (1). From the direction of an entry surface (7) at the cable-end, a bore (6) running coaxially to the optical fiber section also leads into the fusion access aperture. Within the fusion access aperture, the pre-fitted optical fiber section can be welded to the optical fiber (27) of an optical fiber cable (24) in the field. The plug ferrule is assembled from at least two components, of which one (8) possesses the outer jacket serving to center the plug ferrule and the other (10) possesses the fusion access aperture (4) and the bore (6). Both components comprise differing materials, which considerably facilitates manufacture.

Abstract: An optical fiber welding apparatus comprises two casing halves (33) which are rotatable about shafts (51). The casings have their movements coupled to each other by cooperating gear segments and prevent exterior dust particles from reaching the welding location and protects the operator from the welding arc and possible emissions therefrom. The casings (33) have such a shape and are so mounted that they enclose the interior of the apparatus in a space-saving way. On the frame (11) of the welding apparatus, to which the shafts (51) are attached, loose fiber retainers are placed on surfaces intended therefor which have a weak slope. In order to retain the optical fibers an elastic magnetic retainer mechanism (71) is provided in order to press inserted fibers against alignment grooves.

Abstract: An optical device comprises an optical fiber directional coupler having at least a first optical fiber optionally coupled at a coupling region to a second optical fiber such that light can propagate in the coupling region in at least two possible electromagnetic transmission modes; and means for transferring energy between the modes by a spatially periodic perturbation of at least a part of coupling region.

Abstract: For determining an optimal fusion current to be used in welding the ends of two optical fibers to each other the intensity of light emitted from the fibers is measured when heating the fibers by means of currents between welding electrodes. These currents are selected to be significantly lower than the range, in which the optimal fusion current can be expected to be located. From the relation of the measured light intensity values and the different set currents a functional relationship is obtained, which is used for extrapolating to find the current which produces a higher light intensity value, which is the desired one during the actual welding. This is based on the assumption that the light intensity emitted from the fibers is dependent on the current used when heating the fibers in the electric arc between the welding electrodes.

Abstract: Optical fiber attenuators are produced by splicing two fiber ends by melt-fusioning. The fiber ends are initially placed with a large lateral offset and the heating of the spliced portion is continued during a long time period to completely align the fiber ends, in particular the cores (3) and claddings (2) thereof, and to make material of the fibers cores (3) diffuse (23) into the neighbouring regions of the fiber claddings. By properly choosing the extended time for prolonged heating attenuators can be produced with a good repeatability. The prolonged heating period is significantly shortened by the use of a large initial offset.

Abstract: An in-line protection device for protecting fiber optic splices is disclosed. The device includes a rigid body having a central section with an opening sized to receive and house a fiber optic splice between two optical fibers from two fiber optic cables and an end portion having open ends to receive the optical fiber from the fiber optic cable. The fiber optic cables are connected to the rigid body by crimping a sleeve onto the cable and the end portion of the body. A strain relief device is placed over the end portion of the body and fiber optic cable to provide strain relief at either end of the splice protector.

Abstract: One or more parts of an optical fiber is(are) exposed to a high temperature of gas flame for about 30 minutes so as to form one or more radially expanded core part(s) where a diameter of a core of the optical fiber is increased greater than its original size at a center and moderately decreased back to its original size as departing from the center. A part of the transmitting light leaks to the clad at the radially expanded core part. Leaked light hardly travels through the clad from the radially expanded core part to the output end of the optical fiber. This provides a function of an optical attenuator. Also, the attenuation is precisely adjusted to a desired level by controlling a size of the radially expanded core part. Furthermore, as an incident angle of the transmitting light from the core to the clad at the radially expanded core part becomes greater than conventional one, reflecting back the transmitting light to input side is prevented and the reflectance is minimized.

Abstract: A method of packaging a fiber optic coupler formed of a plurality of optical fibers having a coupled region at which electromagnetic waves are coupled therebetween and at least one lead portion extending from the coupled region. A protective body is provided having a receiving space therein. The coupled region and a portion of the at least one lead portion are positioned within the receiving space. A slack in the at least one lead portion is created by affixing two points of the portion of the at least one lead portion to said protective body. The slack is created between the two points.

Abstract: An apparatus for determining the size or other physical properties of particles executing Brownian motion is provided. An integrated fiber optic probe, including a length of a gradient index multimode optical fiber fusion spliced to a monomode optical fiber, delivers laser light to a scattering medium such that the light scattered in the backward direction is collected by another integrated fiber optic probe mounted into the same cylindrical housing. A step index fiber may be fusion spliced between the monomode and gradient index multimode fibers. The axes of the fibers may be collinear or offset. The scattered light, after conversion to a series of photoelectron pulses, is processed to determine the mean particle diameter. The temporal coherence of the scattered field from submicroscopic particles illuminated by laser light is a function of both the integration time and the particle diameter.

Abstract: Uniformity of optical coupling of optical elements such as couplers and splitters is improved by heat treatment which causes dopants in the core of an optical fiber to diffuse into material from the cladding layer of the optical fibers from which the optical element is formed, resulting in a substantially homogeneous interior region of the star coupler or splitter. Increased lossiness of the optical element thus formed may be limited by termination of the heat treatment before dopant diffusion reaches equilibrium throughout the fibers so that a portion of the cladding layer of the fibers remains surrounding the substantially homogeneous region where the fibers have been fused together. Dopant diffusion is constrained to a substantially radial direction in each fiber by uniformity of heating over a region where at least two fibers are twisted together.

Abstract: A wavelength selective optical fiber coupler having various applications in the field of optical communications is disclosed. The coupler is composed of dissimilar waveguides in close proximity. A light induced, permanent index of refraction grating is recorded in the coupler waist. The grating filters and transfers energy within a particular range of wavelengths from a first waveguide to a second waveguide. Transversely asymmetric gratings provide an efficient means of energy transfer. The coupler can be used to combine or multiplex a plurality of lasers operating at slightly different wavelengths into a single fiber. Other embodiments such as a dispersion compensator and gain flattening filter are disclosed.

Abstract: A fused fiber filter coupler is disclosed characterized in that a long period grating is written in at least a portion of the waist of the coupler. The two fibers which make up the coupler have respective propagation constants .beta..sub.fiber1 and .beta..sub.fiber2 which are different and both fibers are singlemode at the wavelength of operation. In order for an efficient grating to be written in the waist of the coupler, the couple must be photosensitive in at least a region of the waist. Since the propagation constant is a function of the wavelength and the period of the grating is given by the expression .LAMBDA.=2 .pi./(.beta..sub.fiber1 -.beta..sub.fiber 2), the filter may be tuned to a particular wavelength by adjusting the period of the grating. The filter so constructed acts in transmission and can discriminate wavelengths of the order of 1 nm.

Abstract: In the determination of the angular rotational position of an axial asymmetry, such as of optically inhomogeneous regions, in an optically transparent body, e.g. stress concentration zones of optical PM-fibers, where the body is located in arbitrary angular start positions, the body is illuminated during rotations thereof to different angular positions around its longitudinal axis. For different angular positions the difference is then determined between light, which has passed through the fiber end and in its position corresponds to the central part of the fiber, and light, which has passed through the fiber end and in its position corresponds to the region of the fiber located immediately outside the central part. These differences, considered as a function of the rotation angle, constitute a curve having a shape typical of the considered body.

Abstract: An optical fiber connector includes a longitudinally extending ferrule having fusion access means defined therein such that an optical fiber stub and a second optical fiber can be fused in the field during installation of the optical fiber connector. In one embodiment, the fusion access means includes a fusion access slot which extends transversely across the ferrule from a first side of the ferrule to a bottom portion of the fusion access slot such that a bore defined longitudinally through the ferrule opens into the fusion access slot. In this embodiment, the radial distance between the bottom portion of the fusion access slot and the second side of the ferrule, opposite the first side, is greater than a predetermined radial distance such that the fusion access slot does not significantly weaken the ferrule so that the ferrule remains structurally intact during use.

Abstract: A method and device is provided wherein a reinforcement is provided for one or more optical fibers. One or more fibers are inserted into a sleeve made of a material that is substantially the same as the material of the cladding of the one or more optical fibers. The bore of the sleeve is sized to accommodate the one or more optical fibers; After the one or more optical fibers is inserted into the sleeve sufficient heat is applied to the sleeve for a duration to collapse the sleeve onto the one or more optical fibers. Preferably, the sleeve is a glass pre-form consisting substantially of 90% or greater silica.

Abstract: A consumable fusion block for fusing optical fibers includes non-conducting substrate with at least one flat surface. A pair of electrodes overlay the flat surface of the substrate and are spaced apart on either side of a passline such that each electrode tip end is adjacent the passline. A space between the electrode tips defines an arc region which can be covered to form a semi-enclosed arc region. A method is also provided for manufacturing a plurality of fusion blocks from a single slab of non-conducting material by overlying the non-conducting material with a length of conducting material, bonding the conducting material to the non-conducting material, and cutting the slab into smaller fusion blocks.

Abstract: A sleeve for protecting and reinforcing a fusion splice of two or more optical fibers. The fusion splice protector includes a heat-shrinkable sleeve adapted to surround the fusion splice and adjacent portions of the fused optical fibers, a stress-relieving support element adjacent the fusion splice, and a hot-melt adhesive contained within the sleeve for retaining the support element adjacent a longitudinal section of the sleeve. The support element is designed to impart varying elasticity along a length of the sleeve such that the fusion splice protector is more rigid at the central portion of the sleeve member than at its ends. This may advantageously be achieved by providing a support element having a cross-sectional profile which varies along the length of the sleeve. The support element is preferably constructed of a polymer or polymer blend, most preferably one having a coefficient of thermal expansion which is approximately equal to the coefficient of thermal expansion of the optical fibers.

Abstract: The present invention relates to an optical fiber filter provided with a portion which selectively reflects or transmits light of a specific wavelength, this portion comprised of a multimode optical fiber in which the refractive index of the core changes periodically along the longitudinal direction thereof. Furthermore, this multimode optical fiber has an input end and an output end, with at least the input end of the multimode optical fiber being connected to a single mode optical fiber. As a result of forming an optical fiber filter in this way, it is possible to realize an optical fiber filter that exhibits no transmission loss at wavelengths other than the center wavelength.

Abstract: An optical fiber splice element is provided that includes a base member having a fusion element for aligning optical fibers for fusion within. A covering member is provided for covering and forming an enclosure with the base member in a closed position. The covering member can be a separate member or alternatively can be in the form of a hinged lid. At lease one of the covering member and the base member include a locking mechanism for maintaining closure in a closed position. The optical fiber splice element in an open position has an opening at either end for accommodating one or more optical fibers.

Abstract: A structurally improved rail-type device for mechanically splicing optical fibers while reducing the splicing loss is disclosed. The above splicing device not only has a cladding clamp with a seesaw structure thereby easily splicing the optical fibers, it also separately moves the covers relative to the body to easily perform the tuning operation. Due to coating clamp's protrusions and body's slots engaging with each other, the coating clamp exclusively vertically move relative to the body and prevent the optical fibers from being axially thrust. The splicing device further seperately clamps the coating and cladding parts of the optical fibers, thereby preventing the spliced fibers from breaking due to tensile or torsional force. The sliding motion of the covers relative to the body is achieved by the rails of the covers and rail grooves of the body.

Abstract: An optical coupler to be used for optical telecommunications is disclosed, characterized by portions of exposed optical fiber sections located immediately adjacent to and outside the respective clots of the first adhesive agent as viewed from the welded optical fiber section being coated by a third adhesive agent having a Young's modulus smaller than that of the first adhesive agent.

Abstract: The orientation of the rotating direction of an optical fiber in an optical fiber array takes the positional axial displacement into consideration. In a method of aligning the orientation of optical fibers, or the axial displacement in an optical fiber array having a plurality of optical fibers, and an optical fiber holding member, an enlarged image of the optical fiber is obtained for each of the optical fibers using an image pick-up means. Then, a distribution of the characterized image corresponding to the positions in the radial direction of the image of the optical fiber are obtained from the enlarged image. From the distribution of the characterized image, the orientation of the rotational direction to the center of the optical fiber, or the positional axial displacement of the core center, is measured.

Abstract: A mass-producible optical attenuation fiber assembly is provided with a first optical fiber with a predetermined attenuation, a second optical fiber connected to a first end of the first optical fiber and a ferrule for fixedly holding the other end of the first optical fiber. In this optical attenuation fiber assembly, the first optical fiber is doped with impurities to achieve a predetermined first attenuation and shortened to obtain a predetermined second attenuation. In the optical attenuation fiber assembly, the second optical fiber may also be cut to a fixed length and the cut edge portion of the second optical fiber may be fixed to another ferrule and polished. The latter ferrule is coupled to the former ferrule through an alignment sleeve.

Abstract: A light branching and coupling device excellent both in transmitting performance and in distributing performance in which the intermediate portion of an optical fiber 10a (10b) is thermally drawn to form light transmission fiber portions 11a and 15a (11b and 15b) and a light branching and coupling fiber portion 13a (13b) having a diameter smaller than that of the light transmission fiber portions and, at the same time, form tapering fiber portions 12a and 14a (12b and 14b) between the light transmission fiber portions and the light branching and coupling fiber portion so that the tapering fiber portions are tapered off gradually toward the light branching and coupling fiber portion 13a (13b) side. The light branching and coupling fiber portions 13a and 13b thus formed are fused with each other.

Abstract: A method of coupling optical parts including bonding the optical coupling faces of two optical waveguides by butting and fusing them. Also, a method for forming a refractive-index distribution having the focusing lens effect by setting the interval between the optical coupling faces of two optical parts to 0.1 mm or more, feeding a refractive-index imaging material also serving as an adhesive into the gap between the faces, and applying light to the refractive-index imaging material from the optical coupling face of at least one of the optical parts.

Abstract: An optical attenuator uses a segment of attenuating fiber interposed in the optical path. The attenuating fiber is produced by using a solution doping technique to introduce transition or rare earth elements into the fiber's core. The dopant reduces the transmission of the fiber. The degree of attenuation depends upon the material used as the dopant, the dopant level, and the length of the attenuation segment. In a specific embodiment, an optical attenuator is provided having a first and second signal carrying optical fibers and an attenuating fiber segment, each of which has a core, a cladding substantially coaxial with the core, and a substantially planar endface. The attenuating fiber segment is fusion spliced between the first and second signal carrying optical fibers. In a second embodiment a portion of the cladding of the attenuating fiber is chemically etched.

Abstract: An optical beam compressor formed of light transparent material for compressing optical signals emitted from an end of an optic fiber. The compressor has a substantially tapered shape extending between a first surface or base having a cross-sectional area, and a second surface or head having a cross-sectional area less than the base area. The compressor has an index of refraction greater than the index of refraction of the environment in which it is disposed, and can be positioned between the end of the optic fiber and a photodetector. Optical signals are provided from the free end of the fiber to the base of the compressor wherein the signals are compressed and transmitted or directed to the photodetector for detection.

Abstract: In splicing two optical fibers in the common way, the end surfaces of the fibers are placed opposite each other and then the fiber ends are melt-fusioned using an electric arc generated between two electrodes. In order to obtain a predetermined lateral displacement of the outer surfaces of the fibers, the fiber ends are placed in positions with a displacement exceeding the desired displacement before the fusion melting. During fusion welding, an electric current of a large intensity is passed between the electrodes, and the first-set lateral displacement will decrease due to surface tension. After the fusion melting, the electric arc is continued at a reduced intensity which also produces a lower temperature in the region at the splice of the fiber ends. At this stage, the outer surfaces of the fiber ends are observed, which then become more and more aligned with each other (that is, the lateral displacement decreases) due to the surface tension.

Abstract: An optical attenuator uses a segment of attenuating fiber interposed in the optical path. The attenuating fiber is produced by using a solution doping technique to introduce transition or rare earth elements into the fiber's core. The dopant reduces the transmission of the fiber. The degree of attenuation depends upon the material used as the dopant, the dopant level, and the length of the attenuation segment. In a specific embodiment, an optical attenuator is provided having a first and second signal carrying optical fibers and an attenuating fiber segment, each of which has a core, a cladding substantially coaxial with the core, and a substantially planar endface. The attenuating fiber segment is fusion spliced between the first and second signal carrying optical fibers. In a second embodiment a portion of the cladding of the attenuating fiber is chemically etched.

Abstract: In a case where an arrayed optical fiber coupler obtained from a tape ribbon 1 is fixed to an reinforcement case 3, a glass portions 2b as a non-elongated portion outside of the elongated portions 2c of the coupler and a protection coating layers 2a at the back thereof are fixed to the reinforcement case 3 with an adhesive layer 4. A collectively coating resin layer 1a of the tape ribbon 1 is not fixed to the reinforcement case 3. The resin layer 1a is fixed to the reinforcement case 3 with a soft adhesive layer 5 different from the above adhesive layer 4, if necessary. As the resin of the adhesive layer 4, there is preferable an adhesive having the viscosity of 50 to 200 P and thermosetting property in addition to ultraviolet cure property.

Abstract: The disclosed method of fusion splicing silica-based optical fiber comprises removing of the polymer coating from the end portions of the respective fibers by contacting the end portions with a chemical polymer remover (e.q., hot sulfuric acid with 5% nitric acid) such that a film of material that comprises the remover remains on the stripped fiber. Typically this is accomplished by refraining from the conventional rinsing of the stripped fiber portions. The film-covered stripped fibers are then fusion spliced in conventional fashion. Splices of strength close to the strength of as-drawn fiber were obtained by this method.

Abstract: A method and apparatus for placing two optical fiber ends or, one optical fiber end and another object, in contact with one another is provided. The method involves moving one of an optical fiber and an object toward one another so that they make contact with one another and apply a loading force upon one another. A load sensing device detects the loading force and provides a signal indicative of the load sensed. The invention is particularly useful for placing two optical fiber ends in contact with one another so that predetermined force applied to the optical fiber ends.

Abstract: Overclad fiber optic couplers are made by inserting the uncoated portions of a plurality of optical fibers into the bore of a glass tube, collapsing the tube midregion onto the fibers and stretching the central portion of the tube midregion. The present method utilizes a glass tube the bore of which includes a circular portion and a recess. A plurality of optical fibers are sequentially inserted into the tube by threading the coated end into the circular bore portion until the uncoated portion of fiber is centered in the tube. The uncoated portion of fiber is then transferred laterally into the bore recess. After all fibers have been threaded into the circular bore portion and transferred to the recess, a filler fiber is inserted into the circular bore portion. The resultant coupler exhibits low excess loss.

Abstract: A method of forming a fusion splice between two optical ribbon cables, which comprises: (i) positioning end portions of the ribbon cables to be spliced in line with one another, and separated from one another by a pre-determined distance; (ii) firing a preparation arc across the ends of the ribbon cables of sufficient energy to soften the ends of the optical fibres forming the ribbon cables and to cause the end of any fibre or fibres (if any) that is/are the most prominent to retract; (iii) firing a fusion arc across the ends of the ribbon cables after a defined period of time following termination of the preparation arc to fuse the ends of the fibres; and (iv) simultaneously with, or subsequent to the fusion arc, moving the ribbon cables toward one another into contact, thereby to effect a fusion splice between the ribbon cables.

Abstract: A method for fabricating an optical attenuator from first and second optical fibers includes placing the fibers in closely spaced overlapped relation to define an overlapped portion of the fibers. Energy is initially applied to the overlapped portion to at least partially fuse the first and second fibers at the overlapped portion.

Abstract: An apparatus for connecting metal tubes covering optical fiber cables includes at least two clamp units 10, 10' for holding a metal sleeve (C5) and two metal tubes (C2, C2') covering two optical fiber cables (C, C') in close position. A laser welding head is placed between two adjacent clamp units. Each clamp unit has a gear (22) as a rotation body to be driven by a drive gear, a clamp device (28, 33, 34) for clamping the metal tube covered optical fiber cables which are introduced in inserting holes (31) where the metal tube covered optical fiber cables are inserted. The clamp device is supported by the rotation body (22) so as to be movable together with the rotation body. The rotation body and the clamp device each are provided with a radially extending selectively open or blocked extraction path (36, 22') to remove, in a radial direction, the metal tube optical fiber cable which has been connected by the apparatus.

Abstract: A consumable fusion block for fusing optical fibers includes non-conducting substrate with at least one flat surface. A pair of electrodes overlay the flat surface of the substrate and are spaced apart on either side of a passline such that each electrode tip end is adjacent the passline. A space between the electrode tips defines an arc region which can be covered to form a semi-enclosed arc region. A method is also provided for manufacturing a plurality of fusion blocks from a single slab of non-conducting material by overlying the non-conducting material with a length of conducting material, bonding the conducting material to the non-conducting material, and cutting the slab into smaller fusion blocks.

Abstract: A method of coupling optical parts including bonding the optical coupling faces of two optical waveguides by butting and fusing them. Also, a method for forming a refractive-index distribution having the focusing lens effect by setting the interval between the optical coupling faces of two optical parts to 0.1 mm or more, feeding a refractive-index imaging material also serving as an adhesive into the gap between the faces, and applying light to the refractive-index imaging material from the optical coupling face of at least one of the optical parts.

Abstract: When splicing optical fibers by melt-fusioning in an electric arc, the electric arc is started, in order to give the fiber splice a large strength, before the ends of the fibers have entered the arc and before they have contacted each other. The arc is in this stage switched on with a low intensity which is increased in the stage when the fiber ends are fusioned to each other. When the electric arc is established having this low intensity and immediately before the contact of the end surfaces and the melt-fusioning, the fiber ends are finely aligned with each other in the lateral direction. It can be performed by way of the optical system and the controller means which are provided in a commercially available fiber welding apparatus, and the fine alignment will give the splice a low attenuation. For standard fibers of the single-mode type a welding current through the electrodes of approximately 6.5 mA is suitable.

Abstract: A fiber-optic laser comprising a birefringent optic fiber possessing a Bragg grating at each of its ends,. A light source emits a light beam having two modes of polarization in the fiber. The birefringence of the fiber makes it possible to keep the two polarization modes separate. The two Bragg gratings are photo-recorded in the fiber and are made in such a way that their resonance wavelength is matched for one polarization. The wave emitted by the fiber is then polarized linearly along P1. Applications to linearly polarized lasers for optical transmission, instrumentation, spectroscopy, medicine, the detection of chemical species and telemetry.

Abstract: A reinforced structure for a multicore optical fiber coupler wherein a longitudinal coating resin of first and second multicore optical fibers, each having a plurality of optical fiber stands positioned in parallel arrangement to each other and each collectively coated with a respective coating resin, is partially removed so as to expose glass portions of the optical fiber strands of each of the optical fibers. The exposed glass portions are then fused and extended. The fused and extended portions are then accommodated in a plurality of grooves formed in a reinforcing casing. The non-extended portions, which are located on opposite ends of the fused and extended portions in the extending direction, are also accommodated on the surface of the reinforcing casing. The optical fibers are secured to the reinforcing casing with adhesive, which is applied to the non-extended portions of the fibers.

Abstract: A sliding-frequency guiding filter for use in the repeater of a soliton transmission system is disclosed. The filter is joined to the output of a soliton amplifier by a fusion splice and consists of a single mode fiber pigtail joined by a fusion splice to each end of an elliptical core fiber having a length L, defined by the following equation:L.sub.FSR =(1/.DELTA.n)[(.lambda..sup.2 /FSR)-.lambda.]where FSR is the free spectral range of the filter, .lambda. is the wavelength of the fundamental mode in the system, and .DELTA.n is the difference between the index of refraction for the fundamental mode and the index of refraction for a higher order mode in the fiber of length L. Since the length, L, is difficult to obtain at the level of precision required, the filters are first measured in order to determine the frequencies of their attenuation peaks and then placed into bins in accordance with the measured wavelength of the attenuation peak.